JP2759620B2 - Resin-coated metal plate and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to abrasion resistance, workability, blackening resistance during processing, punching resistance, corrosion resistance and paintability which can be suitably used for home electric appliances and building materials. The present invention relates to an excellent resin-coated metal sheet, particularly to a resin-coated steel sheet, and to a method for producing such a resin-coated metal sheet, particularly to a resin-coated steel sheet.

[0002]

2. Description of the Related Art Conventionally, as a metal plate used for household electric appliances and building materials, aluminum-plated and stainless steel plates, surface-treated steel plates such as electrogalvanized steel plates and hot-dip galvanized steel plates have been widely used. . Among the,
Conventionally, galvanized surface-treated steel sheets have been subjected to chromate treatment and phosphate treatment, and have been widely used in various components such as household appliances, audio equipment, computer parts, and bottom plates of microwave ovens. ing. But,
In recent years, user needs for these surface-treated steel sheets have been increasingly sophisticated, and various coating performances have been required.

For example, when a surface-treated steel sheet is barely used, corrosion resistance, grounding property, fingerprint resistance that is inconspicuous even when fingerprints are attached, chemical resistance against alkalis and solvents, contamination resistance, and the like are required. Is done. In the case of stamping or punching, lubrication, scratch resistance, deep drawing, die wear, punching, blackening of the working sliding surface, press oil, quick drying Oil resistance such as oil is required.

[0004] When a surface-treated steel sheet is shipped as a product in the form of a coil or sheet from a steel sheet maker, it is usually transported by truck or the like. In the case of a sheet material, the steel sheets overlapping in the package may rub against each other, or scratches may occur on the surface of the steel sheet. These scratches are defects that appear to be discolored in black at those portions, and such defects are called abrasion (abrasion), which significantly degrades the commercial value of the surface-treated steel sheet and makes it difficult for users to use it as a commercial product. Happens.

[0005] Such various needs cannot be met by conventional inorganic surface-treated steel sheets such as chromate treatment and phosphate treatment. Therefore, in recent years, many resin-coated steel sheets having an organic resin film as described below have been proposed. For example, first, JP-A-62-50480 discloses that after a galvanized steel sheet is subjected to chromate treatment, an organic coating containing a carboxylated polyolefin-based resin and an epoxy resin and containing colloidal silica is formed thereon. Accordingly, a galvanized steel sheet having improved corrosion resistance, paintability, solvent resistance, alkali resistance and fingerprint resistance is described. Similarly, second, Japanese Patent Application Laid-Open No. 64-7308
No. 3 discloses ethylene-α, β-containing colloidal sol.
A polymerizable ethylenically unsaturated compound was added to the dispersion of the unsaturated carboxylic acid copolymer resin, emulsion polymerization was carried out, and after the polymerization was completed, a treatment liquid in which the polymer was further crosslinked was prepared and subjected to chromate treatment. Apply to galvanized steel sheet,
A surface-treated steel sheet with improved fingerprint resistance, coin scratch resistance, corrosion resistance, and the like is described.

Third, Japanese Patent Publication No. 5-54823 discloses that a zinc-coated steel sheet is subjected to a chromate treatment, and then a resin comprising an ethylene-ethylene unsaturated carboxylic acid copolymer resin containing colloidal silica and an organic substance having an aziridinyl group. It is described that a resin-coated steel sheet having improved coatability, corrosion resistance, chemical resistance, and scratch resistance can be obtained by applying a liquid and drying to form a crosslinked film.

Fourth, JP-A-6-246229 discloses that a galvanized steel sheet is subjected to a chromate treatment, and ethylene and an α, β-ethylenically unsaturated carboxylic acid are further contained as main components. A description is given of obtaining an organic composite coated steel sheet having improved blackening resistance while maintaining good corrosion resistance by forming a resin coating composed of an ethylene ionomer resin in which 60 to 80% of the bases are neutralized with sodium ions. Have been.

Fifth, Japanese Patent Publication No. 5-13829 discloses that a resin film mainly containing an acrylated epoxy resin and containing fluorine particles and silica particles is formed on a galvanized steel sheet, and the press formability is improved. To obtain a resin-coated steel sheet.

[0009] The first to third prior arts described above relate to corrosion resistance,
Some improvement has been achieved in the performance required for naked use by users, such as paintability and fingerprint resistance. In addition, a certain effect is also recognized with respect to scratch resistance due to handling by the user. However, since these resin-coated steel sheets have inferior hardness and lubricity, the resin coating is removed from the steel sheet by sliding between the resin-coated steel sheet and the mold during press working, particularly, bending and deep drawing. Peeling off, and furthermore, peeling off of the plating layer,
The problem that black matter is generated, adheres to a product, or accumulates in a mold has not been solved. Similarly, with respect to abrasion resistance, it is difficult to prevent abrasion caused by friction between steel sheets due to vibration under extreme pressure.

In the fourth prior art, an ethylene-based resin having a carboxyl group is neutralized with sodium ions and ionized to form a barrier effect by the resin film, thereby preventing corrosion resistance without deteriorating corrosion resistance. Blackening phenomenon of galvanizing under environment, that is,
The blackening resistance is improved. Further, it is presumed that the ionization of the resin component in the resin film can slightly improve the flaw resistance of the film surface, but it has not been improved to the blackening resistance and abrasion resistance during press working.

The fifth prior art relates to a lubricating steel plate for the purpose of improving the press workability, and a remarkable effect can be expected in suppressing the occurrence of black matter and abrasion during press working. However, since the surface of the fluororesin particles used as a lubricant is inactive and it is difficult to chemically bond it to the inside or surface of the resin film, it is treated by electrodeposition coating or powder coating. There is a problem with the coating film adhesion (paintability) when a paint is applied to the surface. In addition, when wax particles are used as a lubricant, when the heating temperature is high at the time of application and drying of the resin film, the wax particles in the resin film soften and float on the film surface and solidify. And the corrosion resistance deteriorates. Therefore, since the drying film forming temperature of the resin film is limited to the softening point of the used wax or less, there is a problem that sufficient film strength cannot be obtained.

[0012]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems in conventional resin-coated metal plates, particularly, resin-coated steel plates. It is excellent in press workability and punching workability such as lubricity, scratch resistance, punching property, blackening resistance during processing, furthermore, corrosion resistance, paintability, grounding property, etc. It is an object of the present invention to provide a well-balanced resin-coated metal plate, particularly a resin-coated steel plate, and a method for producing such a resin-coated metal plate, particularly, a resin-coated steel plate.

[0013]

According to the present invention, an ion
Polyolefin-based copolymers intermolecularly associated with clusters
Based on the unified resin emulsion as the main component, in terms of solid content,
5-30% by weight of silica particles and spherical polyethylene wax
Organized with 0.5 to 20% by weight of particles and aziridinyl groups
The resin coating containing 1 to 20% by weight of the compound
2 to 2.5 g / m ^TwoOn the surface of the metal plate with an adhesion amount in the range of
Provided is a resin-coated metal plate characterized by being
It is.

Further, according to the present invention, 5 to 30% by weight of silica particles and 0.5 of spherical polyethylene wax particles in terms of solid content are mainly composed of a polyolefin copolymer resin emulsion intermolecularly associated with ion clusters. ~
Organic compounds 1-2 having 20% by weight and aziridinyl group
A water-based resin coating containing 0% by weight is applied to the surface of a metal plate, the metal plate is heated, and the coating is dried to obtain a coating amount of 0.
A method for producing a resin-coated metal plate is provided, wherein a resin coating is formed on the surface of the metal plate at a rate of ^{2 to} 2.5 g / m ² .

Hereinafter, a steel plate will be described as a representative of a metal plate. In the present invention, a polyolefin-based copolymer resin emulsion in which molecules are associated with each other by ion clusters is used as a resin component in the resin paint, and the polyolefin-based copolymer resin contains an ethylenically unsaturated carboxylic acid component. An olefin-ethylenically unsaturated carboxylic acid copolymer resin containing from 1 to 40% by weight and optionally containing a (meth) acrylate component is ionomerized, and further crosslinked with a crosslinking agent to obtain a high molecular weight polymer. It is preferable to use a polyolefin-based copolymer resin obtained by polymerization.

The polyolefin copolymer resin emulsion intermolecularly associated with the ion cluster is obtained by a first step of producing a polyolefin copolymer having a carboxyl group and an ionomerization of the polyolefin copolymer thus obtained. And a third step of increasing the molecular weight of the ionomer resin thus obtained.

The polyolefin copolymer resin emulsion obtained by intermolecular association by ion clusters thus obtained is added with predetermined amounts of silica particles, spherical polyethylene wax particles and an organic compound having an aziridinyl group, respectively. According to the present invention, the aqueous resin paint is applied to the surface of a metal plate, the metal plate is heated to a predetermined plate temperature, the paint is dried, and a resin film is formed. It is possible to obtain a resin-coated steel sheet having not only the desired abrasion resistance but also a coating performance that is well-balanced in workability, blackening resistance during processing, punching properties, corrosion resistance, paintability, and the like.

First, in the production of a polyolefin copolymer resin emulsion in which molecules are associated with each other by an ion cluster, the first step of producing a copolymer will be described. An olefin as the first monomer;
Ethylenically unsaturated carboxylic acids as monomers of 1 to 40
% By weight and, if necessary, a monomer mixture comprising another copolymerizable third monomer component in an aqueous dispersion medium at a temperature of 200 to 300 ° C. and a pressure of 1000 to 2000 atm. To prepare a polyolefin-based copolymer resin emulsion having a carboxyl group.

Here, as the ethylenically unsaturated carboxylic acid, for example, (meth) acrylic acid, maleic acid,
Examples thereof include fumaric acid and itaconic acid, and (meth) acrylic acid is particularly preferably used. Among them, (meth) acrylic acid is preferably used. Also,
As the olefin, usually, aliphatic α-olefins such as ethylene and propylene and aromatic vinyl compounds such as styrene are preferably used. Therefore, preferred polyolefin copolymer resins used in the present invention include, for example, ethylene- (meth) acrylic acid copolymer resin, styrene- (meth) acrylic acid copolymer resin, ethylene-styrene- (meth) acrylic acid Copolymer resins and the like can be mentioned.

In the present invention, in addition to the first and second monomers, if necessary, a third monomer such as methyl (meth) acrylate or ethyl (meth) acrylate may be used. (Meth) acrylic acid esters such as propyl methacrylate, styrene-based monomers such as styrene, vinyltoluene, and chlorostyrene; and (meth) acrylic acid such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. ) Hydroxyalkyl acrylate, N-substituted (meth) acrylamide such as N-methylol (meth) acrylamide, epoxy group-containing (meth) acrylate such as glycidyl (meth) acrylate, one kind of (meth) acrylonitrile, Two or more types can be used.

In such a polyolefin-based copolymer resin, when the ethylenically unsaturated carboxylic acid component is more than 40% by weight, the intermolecular molecular weight by ion clusters obtained through the subsequent emulsified ionomer step and high molecular weight step. Even if the associated polyolefin-based copolymer resin emulsion is used as a film-forming material, the resulting resin-coated steel sheet is still insufficient in corrosion resistance. On the other hand, when the ethylenically unsaturated carboxylic acid component is less than 1% by weight in the polyolefin-based copolymer resin, it is difficult to make the obtained polyolefin-based copolymer resin water-soluble or water-dispersible, Not suitable for use in the method of the invention.

As the aqueous dispersion medium, water or a mixture of water and a hydrophilic organic solvent is used. Examples of the hydrophilic organic solvent include lower aliphatic alcohols such as methanol, ethanol and n-propanol, glycol ethers such as ethylene glycol methyl ether, glycol esters such as ethylene glycol acetate, ethers such as tetrahydrofuran and dioxane, and dimethylformamide. , Diacetone alcohol or the like is used.

The polyolefin-based copolymer resin obtained in the first step is then emulsified into an ionomer. This emulsified ionomerization is usually performed at a temperature of 80 to 300 ° C.
The reaction is performed using appropriate cations and, if necessary, aqueous ammonia under a pressure of 1 to 20 atm. When ionomerizing under pressure, it is preferable to use amines in combination from the viewpoint of emulsifying properties and resin performance.

The cation is preferably a metal ion, for example, ions of lithium, potassium, magnesium, zinc, sodium, calcium, iron, aluminum and the like. Usually, sodium ions are particularly preferably used.

According to the present invention, in order to be able to form a resin film having a good balance of workability, blackening resistance during processing, punching resistance, corrosion resistance, paintability, etc., together with abrasion resistance on the surface of a steel sheet, It is necessary to partially crosslink the resin component in the resin paint to increase the molecular weight.

According to the present invention, the ionomerized resin can be further partially cross-linked by a cross-linking agent to obtain a polyolefin copolymer resin having intermolecular association by ion clusters. Here, as the cross-linking agent, any cross-linking agent can be used without particular limitation as long as it can be cross-linked using a carboxyl group of the resin. Therefore, as a crosslinking agent,
For example, a methylol-based compound, an amine-based compound, an epoxy compound, a titanium-based compound, and the like can be given. It is preferable that the crosslinking reaction is usually carried out at a temperature of 30 to 200 ° C. and a pressure of about normal pressure to about 20 atm.

The resin-coated steel sheet according to the present invention is mainly composed of the polyolefin copolymer resin emulsion intermolecularly associated with the ion clusters obtained as described above, and has a silica content of 5 to 30% by weight in terms of solid content. An aqueous resin paint containing 0.5 to 20% by weight of spherical polyethylene wax particles and 1 to 20% by weight of an organic compound having an aziridinyl group is applied on a steel plate, heated to a predetermined plate temperature, and the paint is dried. 0.2% by weight of resin coating after drying
It can be obtained by forming a resin coating on the surface of the steel sheet so as to have a range of 2.5 g / m ² .

The water-based resin coating used in the present invention contains the organic compound having an aziridinyl group in the range of 1 to 20% by weight in terms of solid content as described above. When the paint is applied to a steel sheet and heated and dried, the polyolefin copolymer resin intermolecularly associated with ion clusters as a resin component is cross-linked to form a resin film having a high cross-linking density, and thus the obtained resin film Has remarkably improved hardness, toughness and heat resistance.

The organic compound having an aziridinyl group used in the present invention includes, for example,

[0030]

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Trimethylolpropane tris (β-aziridinylpropionate) represented by the following formula:

[0032]

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Tris-2,4,6- (1-aziridinyl) -1,3,5-triazine represented by the following formula:

[0034]

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Tris [1- (2-methyl)
[Aziridinyl] phosphine oxide. The organic compound having such an aziridinyl group is represented by the following formula:

[0036]

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As shown in the above, a crosslinking reaction is carried out with a copolymer resin having a carboxyl group to form a resin film having a high crosslinking density, and the hardness, toughness and heat resistance of the obtained resin film are remarkably improved. The effect of suppressing the impact due to sliding with the mold and the softening of the resin film due to the heat generated by the mold during press working or punching of the resin-coated steel sheet of the present invention can be obtained. Furthermore, the effect of improving corrosion resistance and chemical resistance can be obtained.

In the resin coating used in the present invention, when the amount of the organic compound having an aziridinyl group is less than 1% by weight in terms of solid content in the coating, the carboxyl group in the copolymer resin as described above is used. Not only is the crosslinking reaction insufficient, but also the carboxyl group reacts with sodium ions and potassium ions in the alkali compound used in the degreasing step after pressing and punching, making the coating hydrophilic. Significantly degrades corrosion resistance and paintability.
On the other hand, when it exceeds 20% by weight, the crosslink density of the coating becomes excessively high, and the coating hardness excessively increases.
It is difficult to follow deformations caused by press working and the like, and cracks and the like occur, thereby deteriorating corrosion resistance and paintability. In particular, in the present invention, the amount of the organic compound having an aziridinyl group in the resin paint is preferably in the range of 5 to 10% by weight in terms of solid content.

The resin coating used in the present invention contains silica particles in a range of 5 to 30% by weight in terms of solid content.
Silica particles provide excellent corrosion resistance and coatability to the obtained resin film, and further improve the hardness of the resin film to cause abrasion due to vibration during transportation, flaws in the film during processing, blackening. This is effective in controlling the occurrence of a chemical phenomenon. However, when the amount of silica particles is less than 5% by weight in terms of solid content in the resin coating, the resulting resin coating is insufficiently improved in corrosion resistance and coatability, and further has a sufficient coating hardness. Cannot be obtained, so that it is impossible to control abrasion resistance, flaws on a coating film during processing, occurrence of a blackening phenomenon, and the like. On the other hand, when it exceeds 30% by weight, the hardness of the resin film is significantly improved, but the ratio of silica particles in the resin film becomes excessively large,
The film-forming property of the resin film deteriorates, cracks occur in the film, and the corrosion resistance deteriorates.

Further, the silica particles act as a lubricant, increase the coefficient of friction of the coating, reduce lubricity, cause wear of the mold during processing, and shorten the life of the mold. Becomes In particular, in the present invention, the amount of silica particles in the resin coating is 5 to 20 in terms of solid content.
A range of weight% is preferred.

In order to maximize the effect of the silica particles as described above, the silica particles should have a particle size of 1 to 200 nm.
Is preferably within the range. As the particle size of the silica particles decreases, the corrosion resistance of the coating improves. The effect of the silica particles is considered to be due to the fact that the resin coating is dense and has excellent adhesion, and the corrosion resistance of the resin coating is further enhanced. From such a viewpoint, the silica particles to be used are better as the particle diameter is smaller, but even if extremely fine particles are used, the above effects are correspondingly not particularly enhanced, so that In the present invention,
Generally, the silica particles may have a particle diameter of 1 nm or more. On the other hand, as the particle size of the silica particles increases, for example, a particle size of 40 to 2 known as chain silica particles
By using the silica particles of 00 nm, the coatability of the resin film is significantly improved. However, when the thickness exceeds 200 nm, the surface of the film is roughened so that a dense resin film cannot be formed, and the silica particles also act as a lubricant, leading to deterioration in workability. In particular, in the present invention, according to the required film performance, for example, when importance is placed on corrosion resistance, the particle size of the silica particles is 4 to 20 n.
m, and in the case where emphasis is placed on paintability, it is preferably in the range of 40 to 200 nm.

Such silica particles are generally known as colloidal silica, and in the present invention, for example, commercially available products such as Snowtex XS, SS, 40, N, UP (manufactured by Nissan Chemical Industries, Ltd.) The product can be used preferably.

The resin coating used in the present invention further comprises:
Spherical polyethylene wax particles were converted to a solid content of 0.5.
-20% by weight. The spherical polyethylene wax particles are effective for improving the lubricity of the obtained resin film and improving the abrasion resistance and the scratch resistance. Furthermore, it improves the deep drawability and punching properties required during press working and punching work, mold wear resistance, blackening resistance of the sliding surface during processing, and imparts excellent workability. .

However, when the amount of the spherical polyethylene wax particles in the resin coating is less than 0.5% by weight in terms of solid content, the resulting resin film has insufficient lubricating properties, resulting in abrasion resistance and resistance to abrasion. It is not possible to improve the flaw resistance and obtain satisfactory workability. On the other hand, when the content exceeds 20% by weight, the obtained resin film has sufficient lubricity, but the coating film adhesion when applied by electrodeposition coating, powder coating, silk printing, or the like. Inferior. One of the causes is that the wax softens and liquefies during application of the resin coating, baking, and drying, and condenses at the interface between the resin coating and the coating, resulting in poor adhesion of the coating. Can be In particular, in the present invention, the amount of the spherical polyethylene wax particles in the resin coating is 1 to 1 in terms of solid content.
A range of 10% by weight is preferred.

In order to maximize the effect of the spherical polyethylene wax particles as described above, the wax particles preferably have a particle size in the range of 0.1 to 3 μm. When the particle diameter of the wax particles is smaller than 0.1 μm, a resin film having excellent lubricating properties cannot be obtained, and not only the resin film but also a punching property based on the wax particles in the film, and a mold resistance. The effect of improving abrasion and deep drawability cannot be obtained.

On the other hand, when the particle size of the wax particles exceeds 3 μm, it becomes difficult to uniformly disperse the wax in the resin coating, and the wax cannot be uniformly dispersed in the obtained resin coating, and Adhesion to steel sheet deteriorates. Further, the adhesion of the coating film by electrodeposition coating, powder coating, silk printing or the like is also deteriorated. In particular, in the present invention, the particle diameter of the spherical polyethylene wax particles in the resin paint,
The range is preferably from 0.3 to 1.0 μm.

In the present invention, the softening point of the spherical polyethylene wax particles is preferably in the range of 80 to 140 ° C. When the softening point is lower than 80 ° C, the wax particles are softened and liquefied with the rise of the mold temperature during press working and punching, so that the sliding surface between the resin-coated steel sheet and the mold is formed. In addition, the liquid liquefaction of the wax occurs, the workability is reduced, scratches and seizure with the mold occur, and the blackened matter adheres to the sliding portion, which significantly deteriorates the product appearance. . On the other hand, when the softening point exceeds 140 ° C., the lubricity of the wax particles is not sufficient, and no improvement in punching properties, mold wear resistance, deep drawability, etc. is recognized, and excellent workability can be obtained. Can not.

In the present invention, such spherical polyethylene wax particles include, for example, Dijet E-17
(Manufactured by Kyogo Chemical Co., Ltd.), KUE-1, KUE-5, KU
E-8, (manufactured by Sanyo Chemical Industries, Ltd.), Chemipearl W-1
00, Chemipearl W-200, Chemipearl W-300,
Chemipearl W-400, Chemipearl W-500, Chemipearl W-640, Chemipearl W-700 (manufactured by Mitsui Petrochemical Industries, Ltd.), Elepon E-20 (Nichika Chemical Co., Ltd.)
Commercially available products, such as MANUFACTURING CORPORATION, can be suitably used.

According to the present invention, the above-mentioned water-based resin coating is applied to the surface of a steel sheet, and when this is heated and dried, it is heated and dried at a sheet temperature lower than the softening point of the spherical polyethylene wax particles. By holding the spherical polyethylene wax particles in the resin film in a spherical shape while forming the resin film, and further improving the lubricity of the resin film thus obtained, the press-working and punching workability of the resin-coated steel sheet obtained is improved. Can be further increased. Further, by keeping the spherical polyethylene wax particles spherical in the resin coating, the wax particles can be more uniformly dispersed in the resin coating, and further, on the surface of the resin coating, the wax exposed from the resin coating can be obtained. Since the ratio of the surface area of the particles can be reduced and the particles can be easily completely covered with the resin film, excellent corrosion resistance and paintability can be obtained.

In order to form a conventional thermosetting resin film on the surface of a steel sheet, it is necessary to bake and dry at a high temperature for a long time. However, the resin paint used in the present invention is applied to the surface of a metal sheet. By heating and drying at a low temperature for a short time, a cross-linked film is formed to form a resin film having a three-dimensional network structure. Therefore, according to the present invention, it is possible to manufacture a crosslinked resin-coated steel sheet with simple drying equipment, and there is an advantage that the steel sheet can be easily manufactured in-line.

For example, in an electrogalvanizing production line, a resin coating is applied by a roll coater and dried in a short time with a simple drying equipment to produce a resin-coated steel sheet. As described above, since in-line production and production with low capital investment are possible, it is possible to contribute to significant cost reduction.

In the present invention, the amount of the resin film adhered to the steel sheet is preferably in the range of 0.2 to 2.5 g / m ² as a dry film. When the amount of the resin coating is less than 0.2 g / m ² , the resin coating cannot be uniformly applied to the steel sheet, and, together with the abrasion resistance, the workability, the blackening resistance, the corrosion resistance, and the coating. The desired balanced film performance such as properties cannot be sufficiently exhibited. On the other hand, when the adhesion amount of the resin coating is more than 2.5 g / m ² , for example,
The grounding property, which is one of the required characteristics in a computer case or the like, that is, the conductivity is deteriorated. Further, in the press working, the amount of the resin film peeled increases, and the release film adheres and accumulates in the mold, causing trouble in press molding and increasing the manufacturing cost. From the viewpoint of practical use, the amount of the resin film attached is preferably in the range of 0.3 to 1.0 g / m ² .

The metal plate material used in the resin-coated metal plate according to the present invention is not particularly limited,
For example, zinc or galvanized steel sheet, aluminum sheet,
Examples include an aluminum alloy plate and a titanium plate. In addition, for zinc or zinc-based plated steel sheet, aluminum sheet, aluminum alloy sheet, etc., from the viewpoint of corrosion resistance, those subjected to a chemical conversion treatment such as chromate treatment or phosphate treatment are preferable, and particularly those subjected to chromate treatment. Is preferred. As the chromate treatment, washing type,
(Reaction type) Chromate treatment, coating type chromate treatment, and electrolytic type chromate treatment are all used.

[0054]

As described above, according to the present invention, it is possible to obtain a resin-coated steel sheet having a crosslinked resin film by applying a water-based paint to a steel sheet and heating and drying it at a relatively low temperature for a short time. it can. The resin-coated steel sheet obtained in this manner is particularly excellent in abrasion resistance, as well as lubricating properties, scratch resistance, punching properties, press working and punching work such as blackening resistance during working, and the like. Has excellent corrosion resistance, paintability, grounding properties, etc., and these properties are well balanced.

[0055]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
In the following, as a metal plate material, an electrogalvanized steel sheet (zinc adhesion amount 20 g / m ² , chromium adhesion amount 20 mg / m ² ) that has been subjected to chromate treatment in order to enable relative evaluation between the examples. Using.

The evaluation items and test methods in the examples are as follows. In the five-point scale, 5 indicates the best and 1 indicates the worst. (1) Corrosion resistance The obtained resin-coated steel sheet was subjected to a salt spray test on edge-sealed plate material and Erichsen-processed material according to JIS Z2.
371, and evaluated by the time until 1% of white rust was generated. The Erichsen extruded height of the Erichsen processed material was 6 mm. (2) Coatability The obtained resin-coated steel sheet is coated with a melamine-based paint to a thickness of 20 μm.
After spray coating, bake at 150 ° C for 30 minutes,
After being immersed in boiling water for 1 hour, take out and after 1 hour, put 100 squares of 1 mm square with a cutter knife, conduct a tape peeling test on this, and paint the film with the number of remaining meshes of the paint film. The adhesion was evaluated.

(3) Dynamic Friction Coefficient In order to evaluate the lubricity of the obtained resin-coated steel sheet, the load due to sliding at a pressure of 150 kg was measured using a sliding test apparatus, and the dynamic friction coefficient was calculated. (4) Punchability In order to evaluate the punching workability of the obtained resin-coated steel sheet, the die material SKD-1 was measured using a continuous punching test apparatus.
1. A continuous punching test was performed under the conditions of a die shape of 10 mm square, a clearance of 25%, a punching speed of 80 sheets / minute, and no punching oil, and the number of punches until the burr height reached 50 μm was evaluated. The state of mold wear after 1.5 million punching was observed with a videoscope, and the mold wear resistance was evaluated on a 5-point scale.

(5) Workability In order to evaluate the press workability such as the deep drawability of the obtained resin-coated steel sheet, a crank press device of 80 tons was used to evaluate the workability.
A single-shot press test was performed, and the abrasion, mold galling, and blackening resistance of the sliding surface of the molded article after molding were visually evaluated on a 5-point scale. (6) Film Hardness A pencil scratch test was performed on the surface of the obtained resin-coated steel sheet according to JIS K5400, and the hardness of the resin film on the surface of the resin-coated steel sheet was evaluated by pencil hardness.

(7) Grounding property The terminals of the tester (+,
−) Was placed lightly, and the resistance of the surface when slid was measured to evaluate the grounding property in five levels. (8) Abrasion resistance Using a PWO type plane bending fatigue tester, abrasion was generated and the ablation resistance was visually evaluated on a five-point scale. (9) Resin coating strength Using a resin paint, prepare a film with a thickness of 40 μm,
Tensile load of the film (film width 1)
(5 mm, 50 mm between chucks, 20 ° C.).

Example 1 A polyolefin copolymer resin having a carboxyl group and having an ethylenically unsaturated carboxylic acid component in the range of 0.5 to 50% by weight was ionomerized with sodium hydroxide, and further treated with a crosslinking agent. The emulsion was polymerized to prepare a polyolefin-based copolymer resin emulsion in which molecules were associated with each other by ion clusters.

The particle diameter is 10 to 20 n in terms of solid content.
m, 10% by weight of silica particles, a softening point of 100 ° C., and a particle diameter of 0.2.
An aqueous resin paint was prepared by adding 5% by weight of 6 μm spherical polyethylene wax particles and 10% by weight of trimethylolpropane tris (β-aziridinylpropionate). This resin paint was applied to the surface of the electrogalvanized steel sheet subjected to the chromate treatment, and was dried by heating at a sheet temperature of 90 ° C.
A resin-coated steel sheet having a resin coating with an adhesion amount of 1 g / m ² was obtained. Table 1 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0062]

[Table 1]

Example 2 A polyolefin copolymer resin having a carboxyl group containing 20% by weight of an ethylenically unsaturated carboxylic acid component was ionomerized with sodium hydroxide, further polymerized with a crosslinking agent, and ion-clustered. To prepare a polyolefin-based copolymer resin emulsion having intermolecular association.

The particle size is 10 to 20 n in terms of solid content.
m, 10% by weight of silica particles, a softening point of 100 ° C., and a particle diameter of 0.2.
An aqueous resin coating was prepared by adding 5% by weight of spherical polyethylene wax particles of 6 μm and trimethylolpropane tris (β-aziridinylpropionate) (TAZM) in the range of 0.5 to 25% by weight. This resin paint was applied to the surface of the electrogalvanized steel sheet subjected to the chromate treatment and dried by heating at a temperature of 90 ° C. to obtain a resin-coated steel sheet having a resin coating with an adhesion amount of 1 g / m ² . Table 2 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0065]

[Table 2]

Example 3 A polyolefin-based copolymer resin having a carboxyl group containing 20% by weight of an ethylenically unsaturated carboxylic acid component was ionomerized with sodium hydroxide and further polymerized with a crosslinking agent to form an ion cluster. To prepare a polyolefin-based copolymer resin emulsion having intermolecular association.

The particle size is 10 to 20 n in terms of solid content.
m of silica particles over a range of 3 to 35% by weight, 5% by weight of spherical polyethylene wax particles having a softening point of 100 ° C. and a particle diameter of 0.6 μm, and trimethylolpropane tris (β-aziridinylpropionate) 10 % By weight to prepare an aqueous resin paint. This resin paint is applied to the surface of the electro-galvanized steel sheet subjected to the chromate treatment, dried by heating at a temperature of 90 ° C., and an adhesion amount of 1 g / m ^2.
A resin-coated steel sheet having a resin coating of Table 3 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0068]

[Table 3]

Example 4 A polyolefin copolymer resin having a carboxyl group containing 20% by weight of an ethylenically unsaturated carboxylic acid component was ionomerized with sodium hydroxide, and further polymerized with a cross-linking agent. To prepare a polyolefin-based copolymer resin emulsion having intermolecular association.

Further, the particle diameter is 4 to 400 in terms of solid content.
10% by weight of silica particles and a softening point of 10
An aqueous resin paint was prepared by adding 5% by weight of spherical polyethylene wax particles having a particle diameter of 0.6 μm at 0 ° C. and 10% by weight of trimethylolpropane tris (β-aziridinylpropionate). This resin paint was applied to the surface of the electrogalvanized steel sheet subjected to the chromate treatment and dried by heating at a temperature of 90 ° C. to obtain a resin-coated steel sheet having a resin coating with an adhesion amount of 1 g / m ² . Table 4 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0071]

[Table 4]

Example 5 A polyolefin copolymer resin having a carboxyl group containing 20% by weight of an ethylenically unsaturated carboxylic acid component was ionomerized with sodium hydroxide, and further polymerized with a cross-linking agent. To prepare a polyolefin-based copolymer resin emulsion having intermolecular association.

The particle size is 10 to 20 n in terms of solid content.
m, 10% by weight of silica particles, a softening point of 100 ° C., and a particle diameter of 0.2.
6 μm spherical polyethylene wax particles are added over a range of 0.3 to 25% by weight and trimethylolpropane tris (β-aziridinylpropionate) 10
The water-based resin coating was prepared by adding wt%. This resin paint is applied to the surface of the electro-galvanized steel sheet subjected to the chromate treatment, dried by heating at a temperature of 90 ° C., and an adhesion amount of 1 g / m 2.
To obtain a resin coated steel sheet having a ^second resin coating. Table 5 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0074]

[Table 5]

Example 6 A polyolefin copolymer resin having a carboxyl group containing 20% by weight of an ethylenically unsaturated carboxylic acid component was ionomerized with sodium hydroxide, and further polymerized with a cross-linking agent. To prepare a polyolefin-based copolymer resin emulsion having intermolecular association.

The particle size is calculated to be 10 to 20 n in terms of solid content.
m silica particles, softening point 100 ° C, particle size
0.1% by weight of spherical polyethylene wax particles ranging from 0.1 to 3 μm and 10% by weight of trimethylolpropane tris (β-aziridinylpropionate)
An aqueous resin paint was prepared. This resin paint was applied to the surface of the electrogalvanized steel sheet subjected to the chromate treatment,
The resultant was dried by heating at 0 ° C. to obtain a resin-coated steel sheet having a resin coating with an adhesion amount of 1 g / m ² . Table 6 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0077]

[Table 6]

Example 7 A polyolefin copolymer resin having a carboxyl group containing 20% by weight of an ethylenically unsaturated carboxylic acid component was ionomerized with sodium hydroxide, further polymerized with a crosslinking agent, and ion-clustered. To prepare a polyolefin-based copolymer resin emulsion having intermolecular association.

Further, the particle diameter is 10 to 20 n in terms of solid content.
10% by weight of spherical polyethylene wax particles having a particle diameter of 0.6 μm and 10% by weight of trimethylolpropane tris (β-aziridinylpropionate) over a range of softening point of 70 to 150 ° C. % To prepare an aqueous resin paint. Applying this resin paint to the surface of the chromated electrogalvanized steel sheet,
It was dried by heating at a temperature of 90 ° C. to obtain a resin-coated steel sheet having a resin coating with an adhesion amount of 1 g / m ² . Table 7 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0080]

[Table 7]

Example 8 A polyolefin copolymer resin having a carboxyl group containing 20% by weight of an ethylenically unsaturated carboxylic acid component was ionomerized with sodium hydroxide, and further polymerized with a cross-linking agent. To prepare a polyolefin-based copolymer resin emulsion having intermolecular association.

The particle size is 10 to 20 n in terms of solid content.
m, 10% by weight of silica particles, a softening point of 100 ° C., and a particle diameter of 0.2.
An aqueous resin paint was prepared by adding 10% by weight of spherical polyethylene wax particles of 6 μm and 10% by weight of trimethylolpropane tris (β-aziridinylpropionate). This resin coating is applied to the surface of the electrogalvanized steel sheet subjected to the chromate treatment, and dried by heating at a temperature of 90 ° C. to have a resin coating having an adhesion amount in the range of 0.2 to 2.5 g / m ^2. I got Table 8 shows the corrosion resistance and coatability of the resin-coated steel sheet thus obtained.

[0083]

[Table 8]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification symbol FI B05D 7/24 301 B05D 7/24 301Q 302 302H 302J 302P (58) Fields investigated (Int.Cl. ⁶ , DB name) B32B 15 / 08 103 B05D 3/02 B05D 5/00 B05D 7/14 B05D 7/24 301 B05D 7/24 302

Claims (12)

(57) [Claims] 1. A polyolefin copolymer resin emulsion in which molecules are associated with each other by means of ion clusters, and 5 to 30% by weight of silica particles, 0.5 to 20% by weight of spherical polyethylene wax particles and aziridinyl in terms of solid content. A resin film containing 1 to 20% by weight of an organic compound having a group is formed on the surface of the metal plate with an adhesion amount in the range of 0.2 to 2.5 g / m ² by dry weight. Resin painted metal plate. 2. A polyolefin copolymer resin emulsion intermolecularly associated with ion clusters containing an ethylenically unsaturated carboxylic acid component in a range of 1 to 40% by weight,
Polyolefin copolymer resin emulsion obtained by ionizing an olefin-ethylenically unsaturated carboxylic acid copolymer resin which may contain a (meth) acrylic acid ester component, and further crosslinking with a crosslinking agent to increase the molecular weight. The resin-coated metal sheet according to claim 1, wherein 3. The resin-coated metal sheet according to claim 2, wherein the olefin is at least one selected from ethylene and styrene. 4. The resin-coated metal sheet according to claim 1, wherein the silica particles have a particle diameter in a range of 1 to 200 nm. 5. The method according to claim 1, wherein the spherical polyethylene wax particles have a particle diameter of 0.1 to 3.
The resin-coated metal plate according to claim 1, which has a particle size in a range of µm. 6. The spherical polyethylene wax particles having a particle size of 80-1.
The resin-coated metal sheet according to claim 1, which has a softening point in a range of 40 ° C. 7. A polyolefin copolymer resin emulsion in which molecules are associated with each other by an ion cluster, and 5 to 30% by weight of silica particles, 0.5 to 20% by weight of spherical polyethylene wax particles, and aziridinyl in terms of solid content. An aqueous resin paint containing 1 to 20% by weight of an organic compound having a group is applied to the surface of a metal plate, the metal plate is heated, and the paint is dried to obtain a coating weight of 0.2 to 2.5 g / m ^2. Forming a resin film on the surface of the metal plate by the method as described above. 8. A polyolefin copolymer resin emulsion intermolecularly associated with ion clusters containing an ethylenically unsaturated carboxylic acid component in a range of 1 to 40% by weight,
Polyolefin copolymer resin emulsion obtained by ionizing an olefin-ethylenically unsaturated carboxylic acid copolymer resin which may contain a (meth) acrylic acid ester component, and further crosslinking with a crosslinking agent to increase the molecular weight. The method for producing a resin-coated metal sheet according to claim 7, wherein 9. The method according to claim 8, wherein the olefin is at least one selected from ethylene and styrene. 10. The method according to claim 7, wherein the silica particles have a particle diameter in the range of 1 to 200 nm. 11. The spherical polyethylene wax particles having a particle diameter of 0.1 to 0.1.
The method for producing a resin-coated metal sheet according to claim 7, which has a particle diameter in a range of 3 µm. 12. The resin-coated metal plate according to claim 7, wherein the metal plate is heated at a temperature lower than the softening point of the spherical polyethylene wax particles to keep the spherical polyethylene wax particles in a spherical shape in the resin coating. Manufacturing method.